1. Field of the Invention
The present invention relates to an adjusting apparatus of a binocular telescope. More precisely, the invention relates to an adjusting apparatus in which an objective lens of one of two telephoto optical systems is moved in the optical axis direction in accordance with the rotational movement of a dioptric correcting device, and in which objective lenses of the telephoto optical systems are moved together in the optical axis direction in accordance with the rotational movement of a focus adjusting device.
2. Description of Related Art
Conventional binocular telescopes, having a pair of juxtaposed telephoto optical systems whose optical axes are parallel, include various adjusting devices, such as a focus adjusting device or a dioptric correcting device for correcting a dioptric difference between a viewer""s eyes, etc. In the case of variable power type binoculars, a power (i.e., magnification) varying device is additionally provided. In general, a binocular telescope has a focus adjusting device which is moved towards the right and left telephoto optical systems and a dioptric correcting devices which independently moves one of the eyepieces to correct a dioptric difference between the eyes of a viewer. Focus adjustment is effected by the focus adjusting device after the dioptric difference is corrected.
In a known adjusting device, an adjusting shaft which is rotated to actuate an adjusting member is provided between right and left telephoto optical systems. The adjusting shaft is rotated by a grip or handle (i.e., operating member) connected thereto. The operating member is exposed to facilitate the rotation of the adjusting shaft.
For instance, once a viewer actuates the dioptric correcting device to adjust the dioptric difference when he or she uses the binocular telescope for the first time, the dioptric correcting device is not actuated again by the same user. The dioptric correcting device is generally not actuated again until another viewer uses the binocular telescope. Accordingly, the location and shape of the operating member of the dioptric difference correcting device are preferably determined so that the operating member can be easily actuated when the dioptric difference is to be adjusted, and is not an obstacle to other binocular operations when adjustment of the dioptric difference is not necessary.
In the focus adjusting device, it is preferable to view an object at a fixed focus determined in accordance with the depth of focus or with the viewer""s naked eyes; particularly when the distance of an object to be viewed can be approximated by infinity, or when there is little difference in the object distance. Consequently, the location and shape of an operating member of the focus adjusting device (i.e., focus adjusting ring) should be determined so that the operating member can be easily actuated when the focus is adjusted and is not an obstacle to other binocular operations when no focus adjustment is necessary.
To this end, the assignee of the present application has proposed an improved adjusting apparatus of a binocular telescope in which an operating member is connected to an adjusting shaft which is rotated to move an adjusting member in the axial direction thereof between an operative position in which the operating member protrudes from a body of the binocular telescope and an inoperative position in which the operating member is retracted into the binocular body {for example, U.S. Pat. No. 5,191,471 based on Japanese Patent application No. 2-336523 (Unexamined Publication No. 4-174411)}. In this binocular telescope, on one hand, the operating member can be easily actuated in the operative position thereof, and on the other hand, it is retracted in the binocular body in the inoperative position.
In applying the proposed adjusting apparatus mentioned above to a dioptric adjusting apparatus in a binocular telescope, the objective lens, of one of the right and left telephoto optical systems, is moved in the optical axis direction to deviate the same from the other telephoto optical system in the optical axis direction to thereby correct the dioptric difference. The focus adjusting ring, coaxial to the adjusting shaft, is rotated to move the dioptic difference correcting objective lens, diopter adjusting shaft, and the other objective lens together.
The primary object of the present invention is to provide an adjusting apparatus of a binocular telescope in which a focus adjusting ring and a dioptric correcting ring have better operability.
To achieve the object mentioned above, according to the present invention, an adjusting apparatus of a binocular telescope with a binocular body including a pair of juxtaposed telephoto optical systems is provided. The adjusting apparatus includes a diopter adjusting shaft for adjusting a difference in diopter between the juxtaposed telephoto optical systems. The diopter is adjusted by rotating the diopter adjusting shaft, and thereby moving an objective lens in one of the pair of juxtaposed telephoto optical systems. A focus adjusting shaft is provided for adjusting a focus of the optical systems. Focus is adjusted by moving the focus adjusting shaft, in a direction parallel to an optical axis. The movement of the focus adjusting shaft moves the diopter adjusting shaft, thereby moves the objective lenses of the pair of optical systems in an integral manner in the optical axis direction. An operation member is provided for rotating the diopter adjusting shaft. A connecting member, for connecting the diopter adjusting shaft and the operating member, is provided so that the diopter adjusting shaft and the operating member are axially movable relative to one another and the relative rotation of the diopter adjusting shaft and the operating member is impeded.
According to another aspect of the present invention, an adjusting apparatus of a binocular telescope is provided and includes a pair of juxtaposed telephoto optical systems having objective lenses an adjusting shaft which is rotated to move the objective lens of one of the telephoto optical systems in an optical axis direction. Also provided are a dioptric correcting member which rotates the adjusting shaft, and a focus adjusting member which is rotated to move the adjusting shaft together with noted objective lens of the one telephoto optical system in the optical axis direction integrally with the objective lens of the other telephoto optical system. The adjusting shaft comprises a first adjusting shaft to be connected to the objective lens of the associated telephoto optical system, and a second adjusting shaft to be connected to the dioptric correcting member. A relative movement permitting mechanism is provided between the first and second adjusting shafts for permitting the first and second adjusting shafts to move relative to one another in the optical axis direction.
The present disclosure relates to subject matter contained in Japanese utility model application No. 05-764 (filed on Jan. 14, 1993) which is expressly incorporated herein by reference in its entirety.